Traditional lensometers comprise an instrument used to determine the power and astigmatism (sphere and cylinder) of a spectacle lens. In particular, traditional lensometers comprise a centered telescopic optical system that includes a reticule and neutralizing lenses that can be employed to measure sphere and cylinder power as well as axis. A dial called the power drum is used in conjunction with an axis dial for introducing test correction such that lines in the reticule appear straight and in focus to the operator. Newer lensometer systems are automatic, however, these instruments still rely on the principle of neutralizing sphere and cylinder utilizing movable lenses.
Such conventional systems and techniques work adequately for lenses measuring sphere and cylinder. The measurement of sphere and cylinder of the spectacle lenses enables optometrists and ophthalmologists to provide conjugate correction for a near-sighted or a far-sighted patient who possibly has astigmatism as well. However, corrective optics provided on the basis of these sphere and cylinder measurements are often not suitable for correcting a person's vision. What is needed are improved systems and methods for measuring refraction of patients and for providing appropriate vision correction.